CN109962722B

CN109962722B - Transmitting device and signal transmission method

Info

Publication number: CN109962722B
Application number: CN201711442840.3A
Authority: CN
Inventors: 赵治磊; 李东
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2017-12-26
Filing date: 2017-12-26
Publication date: 2021-01-05
Anticipated expiration: 2037-12-26
Also published as: WO2019128415A1; EP3723295A1; EP3723295A4; CN109962722A; EP3723295B1

Abstract

The embodiment of the application discloses a sending device and a signal transmission method, which are used for reducing the interference of the transmission of an uplink signal to a downlink frequency band. The transmission device of the embodiment of the application comprises: the AFE comprises at least one low pass filter LPF, each LPF is provided with a filtering frequency point, the AFE is used for acquiring a first signal and filtering the signal higher than the filtering frequency point in the first signal through the LPF to obtain a second signal, and the LD module is used for receiving the second signal. In addition, a signal transmission method is provided, which can reduce the interference of the transmission of the uplink signal to the downlink frequency band.

Description

Transmitting device and signal transmission method

Technical Field

The present application relates to the field of communications, and in particular, to a transmitting apparatus and a signal transmission method.

Background

Each type of digital subscriber line (xDSL) is a technology for data transmission over a pair of twisted pair lines, and includes an Asymmetric Digital Subscriber Line (ADSL), a very high speed digital subscriber line (VDSL), V35, and the like.

The xDSL performs division of uplink and downlink frequency bands by using a frequency division multiplexing method, for example, the V35 frequency band division method includes three uplink frequency bands US0, US1, and US2, and also includes three downlink frequency bands DS1, DS2, and DS3, where US0 corresponds to 25k-138kHz, DS1 corresponds to 138k-3.75MHz, US1 corresponds to 3.75M-5.2MHz, DS2 corresponds to 5.2M-8.5MHz, US2 corresponds to 8.5M-12MHz, and DS3 corresponds to 12M-35MHz, it can be seen that the uplink and downlink frequency bands are mutually crossed, and when uplink and downlink signals are transmitted simultaneously, transmission of the uplink signals may generate additional interference to the downlink frequency bands.

In a user terminal, an uplink signal needs to sequentially pass through a Digital Front End (DFE), an Analog Front End (AFE), a Line Driver (LD) module and a hybrid (H) circuit and finally be transmitted to a twisted pair.

Disclosure of Invention

The embodiment of the application provides a sending device and a signal transmission method, which are used for reducing the interference of the transmission of an uplink signal to a downlink frequency band.

In view of this, a first aspect of the embodiments of the present application provides a transmitting apparatus, including an analog front end AFE and a line driver LD module, where an output end of the AFE is connected to an input end of the LD module, the AFE includes at least one low pass filter LPF, and each LPF is provided with a filtering frequency point;

the AFE is used for acquiring a first signal and filtering out a signal higher than the filtering frequency point in the first signal through the LPF to obtain a second signal;

the LD module is configured to receive the second signal.

It can be understood that different LPFs may be set to the same filtering frequency point, or may be set to different filtering frequency points.

With reference to the first aspect of the present embodiment, in a first implementation manner of the first aspect of the present embodiment, the AFE includes a first LPF, a stable voltage source, a first operational amplifier, and a second operational amplifier;

the first LPF comprises a first resistor, a second resistor, a first capacitor, a second capacitor, a first switch and a second switch, the first switch and the second switch are closed and used for starting the first LPF, the first switch and the second switch are disconnected and used for closing the first LPF, and the first LPF is provided with a first filtering frequency point;

one end of the first resistor is connected with the output end of the first operational amplifier, the other end of the first resistor is connected with the first capacitor, the other end of the first capacitor is connected with the first switch, and the other end of the first switch is connected with the stable voltage source;

one end of the second resistor is connected with the output end of the second operational amplifier, the other end of the second resistor is connected with the second capacitor, the other end of the second capacitor is connected with the second switch, and the other end of the second switch is connected with the stable voltage source.

With reference to the first aspect of the present embodiment, in a second implementation manner of the first aspect of the present embodiment, the AFE includes a second LPF, a first operational amplifier, and a second operational amplifier;

the second LPF comprises a first resistor, a second resistor, a third capacitor and a third switch, the third switch is closed and used for starting the second LPF, the third switch is opened and used for closing the second LPF, and the second LPF is provided with a second filtering frequency point;

one end of the first resistor is connected with the output end of the first operational amplifier, the other end of the first resistor is connected with the third capacitor, the other end of the third capacitor is connected with the third switch, the other end of the third switch is connected with the second resistor, and the other end of the second resistor is connected with the output end of the second operational amplifier.

With reference to the first implementation manner of the first aspect of the embodiment of the present application, in a third implementation manner of the first aspect of the embodiment of the present application, the AFE further includes a third LPF;

the third LPF comprises a first resistor, a second resistor and a fourth capacitor, and is provided with a third filtering frequency point;

one end of the first resistor is connected with the output end of the first operational amplifier, the other end of the first resistor is connected with the first capacitor, the connecting point is connected with the fourth capacitor, the other end of the first capacitor is connected with the first switch, and the other end of the first switch is connected with the stable voltage source;

one end of the second resistor is connected with the output end of the second operational amplifier, the other end of the second resistor is connected with the second capacitor, the connecting point is connected with the other end of the fourth capacitor, the other end of the second capacitor is connected with the second switch, and the other end of the second switch is connected with the stable voltage source.

With reference to the second implementation manner of the first aspect of the embodiment of the present application, in a fourth implementation manner of the first aspect of the embodiment of the present application, the AFE further includes a third LPF;

one end of the first resistor is connected with the output end of the first operational amplifier, the other end of the first resistor is connected with the third capacitor, the connecting point of the first resistor is connected with the fourth capacitor, the other end of the third capacitor is connected with the third switch, the other end of the third switch is connected with the second resistor, the connecting point of the third switch is connected with the other end of the fourth capacitor, and the other end of the second resistor is connected with the output end of the second operational amplifier.

With reference to the first aspect of the embodiment of the present application, or the first implementation manner of the first aspect of the embodiment of the present application, or the second implementation manner of the first aspect of the embodiment of the present application, or the third implementation manner of the first aspect of the embodiment of the present application, or the fourth implementation manner of the first aspect of the embodiment of the present application, in a fifth implementation manner of the first aspect of the embodiment of the present application, the LD module includes a third operational amplifier, a fourth operational amplifier, a third resistor, a fourth LPF, and a fifth LPF;

the fourth LPF comprises a fourth resistor, a fifth capacitor and a fourth switch, the fourth switch is used for starting the fourth LPF, the fourth switch is used for closing the fourth LPF, and the fourth LPF is provided with a fourth filtering frequency point;

the fifth LPF comprises a fifth resistor, a sixth capacitor and a fifth switch, the fifth switch is closed and used for starting the fifth LPF, the fifth switch is opened and used for closing the fifth LPF, and the fifth LPF is provided with a fifth filtering frequency point;

the output end of the third operational amplifier is connected with the fourth resistor, the connecting point is connected with the fifth capacitor, the other end of the fourth resistor is connected with one input end of the third operational amplifier, the connecting point is connected with the fourth switch and the third resistor, and the other end of the fourth switch is connected with the other end of the fifth capacitor;

the output end of the fourth operational amplifier is connected with the fifth resistor, the connecting point is connected with the sixth capacitor, the other end of the fifth resistor is connected with one input end of the fourth operational amplifier, the connecting point is connected with the fifth switch and the other end of the third resistor, and the other end of the fifth switch is connected with the other end of the sixth capacitor.

With reference to the fifth implementation manner of the first aspect of the embodiment of the present application, in a sixth implementation manner of the first aspect of the embodiment of the present application, the LD module further includes a sixth LPF and a seventh LPF;

the sixth LPF comprises the fourth resistor and a seventh capacitor, and is provided with a sixth filtering frequency point;

the seventh LPF comprises the fifth resistor and an eighth capacitor, and is provided with a seventh filtering frequency point;

the output end of the third operational amplifier is connected with the fourth resistor, the connecting point is connected with the fifth capacitor and the seventh capacitor, the other end of the fourth resistor is connected with one input end of the third operational amplifier, the connecting point is connected with the other ends of the fourth switch, the third resistor and the seventh capacitor, and the other end of the fourth switch is connected with the other end of the fifth capacitor;

the output end of the fourth operational amplifier is connected with the fifth resistor, the connecting point is connected with the sixth capacitor and the eighth capacitor, the other end of the fifth resistor is connected with one input end of the fourth operational amplifier, the connecting point is connected with the fifth switch, the other end of the third resistor and the other end of the eighth capacitor, and the other end of the fifth switch is connected with the other end of the sixth capacitor.

A second aspect of the embodiments of the present application provides a transmitting apparatus, including an analog front end AFE and a line driver LD module, where an output end of the AFE is connected to an input end of the LD module, the LD module includes at least one low pass filter LPF, and each LPF is provided with a filtering frequency point;

the AFE is used for acquiring a first signal and sending the first signal to the LD module;

and the LD module is used for receiving the first signal and filtering the signals higher than the filtering frequency point in the first signal through the LPF to obtain a second signal.

With reference to the second aspect of the present embodiment, in the first real-time mode of the second aspect of the present embodiment, the LD module includes a third operational amplifier, a fourth operational amplifier, a third resistor, a fourth LPF, and a fifth LPF;

With reference to the first implementation manner of the second aspect of the embodiment of the present application, in the second real-time implementation manner of the second aspect of the embodiment of the present application, the LD module further includes a sixth LPF and a seventh LPF;

With reference to the second aspect of the present application, or the first implementation manner of the second aspect of the present application, or the second implementation manner of the second aspect of the present application, in a third implementation manner of the second aspect of the present application, the AFE includes a first LPF, a stable voltage source, a first operational amplifier, and a second operational amplifier;

With reference to the second aspect of the present application, or the first implementation manner of the second aspect of the present application, or the second implementation manner of the second aspect of the present application, in a fourth implementation manner of the second aspect of the present application, the AFE includes a second LPF, a first operational amplifier, and a second operational amplifier;

the second LPF comprises a first resistor, a second resistor, a third capacitor and a third switch, the third switch is closed and used for starting the third LPF, the third switch is opened and used for closing the second LPF, and the second LPF is provided with a second filtering frequency point;

With reference to the third implementation manner of the second aspect of the embodiments of the present application, in a fifth implementation manner of the second aspect of the embodiments of the present application, the AFE further includes a third LPF;

With reference to the fourth implementation manner of the second aspect of the embodiment of the present application, in a sixth implementation manner of the second aspect of the embodiment of the present application, the AFE further includes a third LPF;

A third aspect of the embodiments of the present application provides a signal transmission method, including:

acquiring a first signal;

filtering out a signal higher than a filtering frequency point in the first signal by using a Low Pass Filter (LPF) to obtain a second signal, wherein the LPF is provided with the filtering frequency point;

outputting the second signal.

With reference to the third aspect of the embodiment of the present application, in a first implementation manner of the third aspect of the embodiment of the present application, filtering, by the LPF, a signal higher than the filtering frequency point in the first signal to obtain a second signal includes:

determining the filtering frequency point according to the transmission frequency band of the first signal, wherein the filtering frequency point is greater than or equal to the highest frequency point of the transmission frequency band;

and starting the LPF corresponding to the filtering frequency point, and filtering the first signal to obtain the second signal.

According to the technical scheme, the embodiment of the application has the following advantages:

in the embodiment, a sending device is provided, which includes an AFE and an LD module, wherein an output end of the AFE is connected to an input end of the LD module, the AFE includes at least one LPF, each LPF is provided with a filtering frequency point, the AFE is configured to obtain a first signal, and a signal higher than the filtering frequency point in the first signal is filtered by the LPF to obtain a second signal, and the LD module is configured to receive the second signal.

Drawings

Fig. 1 is a schematic diagram of the frequency band division of V35;

fig. 2 is a schematic flow diagram of an uplink signal in a user equipment;

FIG. 3 is a schematic diagram of an embodiment of a transmitting apparatus of the present application;

FIG. 4 is a schematic diagram of another embodiment of a transmitting apparatus of the present application;

FIG. 5 is a schematic diagram of another embodiment of a transmitting apparatus of the present application;

FIG. 6 is a schematic diagram of another embodiment of a transmitting apparatus of the present application;

FIG. 7 is a schematic diagram of another embodiment of a transmitting apparatus of the present application;

FIG. 8 is a schematic diagram of another embodiment of a transmitting apparatus of the present application;

FIG. 9 is a schematic diagram of another embodiment of a transmitting apparatus of the present application;

FIG. 10 is a schematic diagram of another embodiment of a transmitting apparatus of the present application;

fig. 11 is a schematic diagram of an embodiment of the signal transmission method of the present application.

Detailed Description

The embodiment of the application is realized on the basis of an xDSL technology, wherein the xDSL comprises ADSL, VSDL, V35 and the like, the xDSL divides uplink and downlink frequency bands by adopting a frequency division multiplexing mode, as shown in fig. 1, the frequency band division mode of V35 comprises three uplink frequency bands, namely US0, US1 and US2, and three downlink frequency bands, namely DS1, DS2 and DS3, wherein the uplink frequency bands refer to signal frequency bands sent from user terminal equipment to local side equipment; the downlink frequency band refers to a signal frequency band of the user terminal device sent from the central office device, the uplink and downlink signals perform data transmission simultaneously, the frequency bands are intersected with each other, when the user terminal device sends the uplink signal, extra noise is generated in the downlink frequency band, and the performance of the downlink receiving frequency band is affected by the extra noise.

The sending device in the embodiment of the present application may be a user terminal device, where the signal trend when the user terminal device sends an uplink signal is as shown in fig. 2, the DFE modulates digital information and transmits the modulated signal to the AFE, the AFE converts the digital signal into an analog signal and transmits the analog signal to the LD module, and the LD module amplifies the signal transmitted by the AFE and transmits the analog signal to the H circuit, and finally outputs the amplified signal to the twisted pair line.

In order to effectively reduce the interference of the transmission of the uplink signal to the downlink frequency band, the transmitting apparatus in this embodiment of the present application sets a Low Pass Filter (LPF) in the AFE and/or LD module, so as to filter a part of signals higher than the filtering frequency point of the LPF, it can be understood that there are various setting modes for the LPF in this embodiment of the present application, and the following description is respectively provided with reference to the accompanying drawings:

firstly, at least one LPF is arranged in the AFE.

Referring to fig. 3, an AFE of a transmitting apparatus according to an embodiment of the present invention includes:

the voltage regulator includes a stable voltage source, a first operational amplifier a1, a second operational amplifier a2, and a first LPF, wherein the first LPF specifically includes a first resistor R1, a second resistor R2, a first capacitor C1, a second capacitor C2, a first switch S1, and a second switch S2, and it is understood that the stable voltage source is generally a dc operating voltage of the amplifier circuit, that is, a common mode Voltage (VCM), and therefore, in the embodiment of the present application, the stable voltage source may be represented by VCM, and after the limitation, the following limitation is not repeated.

The first switch S1 and the second switch S2 are closed to turn on the first LPF, the first switch S1 and the second switch S2 are opened to turn off the first LPF, and the first LPF is provided with a first filtering frequency point;

one end of a first resistor R1 is connected with the output end of the first operational amplifier A1, the other end of the first resistor R1 is connected with a first capacitor C1, the other end of the first capacitor C1 is connected with a first switch S1, and the other end of the first switch S1 is connected with the VCM;

one end of the second resistor R2 is connected to the output end of the second operational amplifier a2, the other end of the second resistor R2 is connected to the second capacitor C2, the other end of the second capacitor C2 is connected to the second switch S2, and the other end of the second switch S2 is connected to the VCM.

In the embodiment of the application, the AFE acquires the first signal from the DFE, and filters out a signal higher than the first filtering frequency point in the first signal through the first LPF to obtain a second signal, and outputs the second signal to the LD module.

Specifically, the first filtering frequency point can be set to 138KHz, when signals are transmitted in a long distance, only the US0 uplink frequency band is used, at the moment, the first switch S1 and the second switch S2 are controlled to be closed, the first LPF is enabled to be effective, the signals higher than 138KHz are filtered, when the signals are transmitted in a short distance, the US0, the US1 and the US2 uplink frequency bands are all used, at the moment, the first switch S1 and the second switch S2 are controlled to be disconnected, the first LPF is disabled, and it is ensured that full-band signals can be normally transmitted.

It is understood that the first filtering frequency point may be set to other values besides 138KHz, for example, to 5.2MHz, which is not limited herein.

Please refer to fig. 4, the AFE may further use a second LPF to replace the first LPF to achieve the same filtering effect, and includes a first operational amplifier a1, a second operational amplifier a2, and a second LPF, wherein the second LPF includes a first resistor R1, a second resistor R2, a third capacitor C3, and a third switch S3;

the third switch S3 is closed to turn on the second LPF, the third switch S3 is opened to turn off the second LPF, and the second LPF is provided with a second filtering frequency point;

one end of the first resistor R1 is connected to the output end of the first operational amplifier a1, the other end of the first resistor R1 is connected to the third capacitor C3, the other end of the third capacitor C3 is connected to the third switch S3, the other end of the third switch S3 is connected to the second resistor R2, and the other end of the second resistor R2 is connected to the output end of the second operational amplifier a 2.

In this embodiment of the application, the AFE acquires the first signal from the DFE, and filters out a signal higher than the second filtering frequency point in the first signal by the second LPF to obtain a second signal, and outputs the second signal to the LD module.

The description of the second filtering frequency point is similar to the description of the first filtering frequency point in the embodiment shown in fig. 3, and details thereof are not repeated here.

It should be noted that, the AFE may further include two LPFs, please refer to fig. 5, the AFE further includes a third LPF, where the third LPF includes a first resistor R1, a second resistor R2, and a fourth capacitor C4, and the third LPF is provided with a third filtering frequency point;

one end of a first resistor R1 is connected with the output end of the first operational amplifier A1, the other end of the first resistor R1 is connected with a first capacitor C1, the connection point is connected with a fourth capacitor C4, the other end of the first capacitor C1 is connected with a first switch S1, and the other end of the first switch S1 is connected with the VCM;

one end of a second resistor R2 is connected to the output end of the second operational amplifier a2, the other end of the second resistor R2 is connected to the second capacitor C2, the connection point is connected to the other end of the fourth capacitor C4, the other end of the second capacitor C2 is connected to a second switch S2, and the other end of the second switch S2 is connected to VCM.

In the embodiment of the present application, when the first switch S1 and the second switch S2 are turned off, the AFE performs filtering through the LPF consisting of the first resistor R1, the second resistor R2 and the fourth capacitor C4, and when the first switch S1 and the second switch S2 are turned on, the AFE performs filtering through the LPF consisting of the first resistor R1, the second resistor R2, the first capacitor C1, the second capacitor C2 and the fourth capacitor C4, the two LPFs may set different filtering frequency points, so that different filtering effects are achieved by controlling the turning on or off of the first switch S1 and the second switch S2, for example, the filtering frequency point of the LPF that functions when the first switch S1 and the second switch S2 are turned off is set to a relatively high value such as 12MHz, the filtering frequency point of the LPF that functions when the first switch S1 and the second switch S2 are turned on is set to a relatively low value such as 5.2MHz, and the highest filtering frequency point used by the current US2, the first switch S1 and the second switch S2 are opened to make the filtering frequency points 12MHz and LPF functional, and if the highest frequency band used by the current uplink signal is US1, the first switch S1 and the second switch S2 are closed to make the filtering frequency points 5.2MHz and LPF functional.

Similarly, referring to fig. 6, the AFE further includes a third LPF, where the third LPF includes a first resistor R1, a second resistor R2, and a fourth capacitor C4, and the third LPF has a third filtering frequency point;

one end of the first resistor R1 is connected to the output end of the first operational amplifier a1, the other end of the first resistor R1 is connected to the third capacitor C3, and the connection point is connected to the fourth capacitor C4, the other end of the third capacitor C3 is connected to the third switch S3, the other end of the third switch S3 is connected to the second resistor R2, and the connection point is connected to the other end of the fourth capacitor C4, and the other end of the second resistor R2 is connected to the output end of the second operational amplifier a 2.

In this embodiment, when the third switch S3 is turned off, the AFE performs filtering through the LPF composed of the first resistor R1, the second resistor R2, and the fourth capacitor C4, and when the third switch is turned off, the AFE performs filtering through the LPF composed of the first resistor R1, the second resistor R2, the third capacitor C3, and the fourth capacitor C4, and the two LPFs may set different filtering frequency points, so that different filtering effects are achieved by controlling the on or off of the third switch S3.

And secondly, arranging at least one LPF in the LD module.

Referring to fig. 7, an LD module of a transmitting apparatus in an embodiment of the present application includes:

a third operational amplifier A3, a fourth operational amplifier A4, a third resistor R3, a fourth LPF, and a fifth LPF;

the fourth LPF comprises a fourth resistor R4, a fifth capacitor C5 and a fourth switch S4, the fourth switch S4 is closed and used for starting the fourth LPF, the fourth switch S4 is opened and used for closing the fourth LPF, and the fourth LPF is provided with a fourth filtering frequency point;

the fifth LPF comprises a fifth resistor R5, a sixth capacitor C6 and a fifth switch S5, the fifth switch S5 is closed and used for turning on the fifth LPF, the fifth switch is opened and used for turning off the fifth LPF, and the fifth LPF is provided with a fifth filtering frequency point;

the output end of the third operational amplifier A3 is connected with a fourth resistor R4, the connection point is connected with a fifth capacitor C5, the other end of the fourth resistor R4 is connected with one input end of the third operational amplifier A3, the connection point is connected with a fourth switch S4 and a third resistor R3, and the other end of the fourth switch S4 is connected with the other end of the fifth capacitor C5;

the output end of the fourth operational amplifier a4 is connected to a fifth resistor R5, and the connection point is connected to the sixth capacitor C6, the other end of the fifth resistor R5 is connected to one input end of the fourth operational amplifier a4, and the connection point is connected to the other ends of the fifth switch S5 and the third resistor R3, and the other end of the fifth switch S5 is connected to the other end of the sixth capacitor C6.

In the embodiment of the application, the LD module receives the first signal sent from the AFE, and filters a signal higher than a filtering frequency point in the first signal by the LPF to obtain a second signal, so as to output the second signal.

It can be understood that the fourth switch S4 and the fifth switch S5 need to be turned on or off simultaneously, and the fourth LPF and the fifth LPF have the same filtering frequency point, that is, the fourth LPF and the fifth LPF work together to filter the first signal.

In this embodiment, a sending device is provided, which includes an AFE and an LD module, wherein an output end of the AFE is connected to an input end of the LD module, the LD module includes at least one LPF, each LPF is provided with a filtering frequency point, the AFE is configured to obtain a first signal, the LD module is configured to receive the first signal sent by the AFE, and a second signal is obtained by filtering a signal higher than the filtering frequency point in the first signal through the LPF.

Referring to fig. 8, a sixth LPF and a seventh LPF may be further disposed in the LD module;

the sixth LPF comprises a fourth resistor R4 and a seventh capacitor C7, and a sixth filtering frequency point is arranged on the sixth LPF;

the seventh LPF comprises a fifth resistor R5 and an eighth capacitor C8, and is provided with a seventh filtering frequency point;

the output end of the third operational amplifier A3 is connected with a fourth resistor R4, and the connection point is connected with the fifth capacitor C5 and the seventh capacitor C7, the other end of the fourth resistor R4 is connected with one input end of the third operational amplifier A3, the connection point is connected with the other ends of the fourth switch S4, the third resistor R3 and the seventh capacitor C7, and the other end of the fourth switch S4 is connected with the other end of the fifth capacitor C5;

the output end of the fourth operational amplifier a4 is connected to the fifth resistor R5, the connection point is connected to the sixth capacitor C6 and the eighth capacitor C8, the other end of the fifth resistor R5 is connected to one input end of the fourth operational amplifier a4, the connection point is connected to the other ends of the fifth switch S5, the third resistor R3 and the eighth capacitor C8, and the other end of the fifth switch S5 is connected to the other end of the sixth capacitor C6.

It can be understood that, the fourth switch S4 and the fifth switch S5 need to be turned on or off simultaneously, when the fourth switch S4 and the fifth switch S5 are turned off, the sixth LPF and the seventh LPF work together, the filtering frequency points of the sixth LPF and the seventh LPF can be set to a relatively high value, for example, 12MHz, to filter the partial signal higher than 12MHz in the first signal, and when the fourth switch S4 and the fifth switch S5 are turned on, the LPF composed of the fourth resistor R4, the fifth resistor R5, the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7, and the eighth capacitor C8 functions to set the filtering frequency point of the LPF to a relatively low value, for example, 5.2MHz, to filter the partial signal higher than 5.2MHz in the first signal, so that the fourth switch S4 and the fifth switch S5 can be controlled to be turned on or off according to the currently used frequency band of the uplink signal to achieve different filtering effects, for example, when the highest frequency band used by the current uplink signal is US2, the fourth switch S4 and the fifth switch S5 are opened to operate the LPF having a filtering frequency point of 12MHz, and when the highest frequency band used by the current uplink signal is US1, the fourth switch S4 and the fifth switch S5 are closed to operate the LPF having a filtering frequency point of 5.2 MHz.

And thirdly, at least one LPF is arranged in each of the AFE module and the LD module.

Referring to fig. 9, the AFE is provided with a first LPF, and the LD module is provided with a fourth LPF and a fifth LPF;

specifically, one end of a first resistor R1 is connected to the output end of the first operational amplifier a1, the other end of the first resistor R1 is connected to a first capacitor C1, the other end of the first capacitor C1 is connected to a first switch S1, and the other end of the first switch S1 is connected to the VCM;

one end of a second resistor R2 is connected with the output end of the second operational amplifier A2, the other end of the second resistor R2 is connected with a second capacitor C2, the other end of the second capacitor C2 is connected with a second switch S2, and the other end of the second switch S2 is connected with the VCM;

It should be noted that, the LPF in the AFE and the LPF in the LD module may be set to the same filtering frequency point, so as to enhance the filtering effect in a specific mode, for example, the frequency band used by the uplink signal is US0, then the filtering frequency point is set to 138KHz, the first signal may be filtered twice when passing through the AFE and LD modules to obtain the second signal, in addition, the LPF in the AFE and the LPF in the LD module may also be set to different filtering frequency points, so as to achieve the filtering effect in different modes, for example, the filtering frequency point of the LPF in the AFE is set to 138KHz, the filtering frequency point of the LPF in the LD module is set to 5.2MHz, then when the highest frequency band used by the uplink signal is US0, the LPF in the AFE is turned on, and when the highest frequency band used by the uplink signal is US1, the LPF in the AFE is turned off, and the LPF in the.

It is understood that, in this embodiment, the setting manner of the LPF in the AFE may also be transformed as shown in fig. 4, fig. 5, or fig. 6, and the setting of the LPF in the LD module may also be transformed as shown in fig. 8, which is not described herein again specifically.

Referring to fig. 10, the following describes a case where the AFE and LD modules both include a plurality of LPFs;

specifically, one end of a first resistor R1 is connected to the output end of the first operational amplifier a1, the other end of the first resistor R1 is connected to a first capacitor C1, and the connection point is connected to a fourth capacitor C4, the other end of the first capacitor C1 is connected to a first switch S1, and the other end of the first switch S1 is connected to the VCM;

one end of a second resistor R2 is connected with the output end of the second operational amplifier A2, the other end of the second resistor R2 is connected with a second capacitor C2, the connection point is connected with the other end of a fourth capacitor C4, the other end of the second capacitor C2 is connected with a second switch S2, and the other end of the second switch S2 is connected with the VCM;

In this embodiment, the filtering effects of multiple different modes can be achieved by controlling the opening and closing of the first switch S1, the second switch S2, the fourth switch S4 and the fifth switch S5, for example, the filtering frequency point of the LPF consisting of the first resistor R1, the second resistor R2 and the fourth capacitor C4 is set to 12 MHz; the filtering frequency point of an LPF (low pass filter) consisting of the fourth resistor R4, the seventh capacitor C7, the fifth resistor R5 and the eighth capacitor C8 is set to be 12 MHz; when the fourth switch S4 and the fifth switch S5 are closed, the LPF filter frequency point formed by the fourth resistor R4, the fifth resistor R5, the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7, and the eighth capacitor C8 is set to 5.2 MHz; (ii) a When the first switch S1 and the second switch S2 are closed, the filtering frequency of the LPF consisting of the first resistor R1, the second resistor R2, the first capacitor C1, the second capacitor C2, and the fourth capacitor C4 is set to 138 KHz.

When the highest frequency band used by the uplink signal is US2, the first switch S1, the second switch S2, the fourth switch S4 and the fifth switch S5 are turned off, and the LPF having a filtering frequency point of 12MHz functions; when the highest frequency band used by the uplink signal is US1, the first switch S1 and the second switch S2 are opened, the fourth switch S4 and the fifth switch S5 are closed, and the LPF with the filtering frequency point of 5.2MHz plays a role; when the highest frequency band used by the uplink signal is US0, the first switch S1 and the second switch S2 are closed, and the LPF with the filtering frequency point of 138KHz plays a role.

The embodiments of the present application are described above from the perspective of a transmitting apparatus, and a signal transmission method applied to the transmitting apparatus is described below:

referring to fig. 11, an embodiment of a signal transmission method in the embodiment of the present application includes:

1101. a first signal is acquired.

In the embodiment of the present application, the obtained first signal is an uplink signal that the user terminal device needs to send to the central office device.

1102. A transmission frequency band of the first signal is determined.

In the embodiment of the present application, the transmission band of the first signal may be determined according to one or more parameters such as an operation mode, a loop distance, a signal-to-noise ratio, or a line attenuation, for example, in an ADSL operation mode, the transmission band of the first signal is US0 and US1, and in a VDSL or V35 operation mode, the transmission band of the first signal is US0, US1, and US 2; for another example, the transmission frequency band of the first signal may be different depending on the loop distance, and in the case of long-distance transmission, only US0 may be available, while in the case of short-distance transmission, US0, US1, and US2 may all be available.

1103. And determining a filtering frequency point according to the transmission frequency band of the first signal.

In the embodiment of the present application, after the transmission frequency band of the first signal is determined, filtering frequency points may be determined according to the transmission frequency band of the first signal, and it can be understood that the filtering frequency points should be greater than or equal to the highest frequency point of the transmission frequency band, taking the transmission frequency bands of US0, US1, and US2 as examples, then the corresponding filtering frequency points should be set to 138KHz, 5.2MHz, and 12MHz, respectively.

1104. And starting an LPF corresponding to the filtering frequency point to filter the first signal to obtain a second signal.

In the embodiment of the present application, after the filtering frequency point is determined, the LPF corresponding to the filtering frequency point is turned on to filter the first signal to obtain the second signal, it can be understood that, for different scenes, the filter provided with different filtering frequency points can be selectively turned on according to actual conditions, and the specific implementation manner is similar to the description in the embodiments shown in fig. 3 to fig. 10, and is not repeated here.

1105. And outputting a second signal.

In the embodiment of the present application, after the first signal is filtered to obtain the second signal, the second signal is further output to the twisted pair.

While the transmitting device and the signal transmission method provided in the present application have been described in detail, those skilled in the art will appreciate that the present invention is not limited to the above embodiments, and that the present invention is not limited to the above embodiments.

Claims

1. A sending device comprises an analog front end AFE and a line driver LD module, and is characterized in that the output end of the AFE is connected with the input end of the LD module, the AFE comprises at least one LPF, the LD module comprises at least one LPF, and each LPF is provided with a filtering frequency point; the LPF in the AFE comprises at least one switch for controlling the LPF in the AFE to be switched on or off; the LPF in the LD module comprises at least one switch for controlling the on or off of the LPF in the LD module;

if the LPF in the AFE is turned on and the LPF in the LD module is turned off, the AFE is used for acquiring a first signal and filtering the first signal through the LPF in the AFE to obtain a second signal; the LD module is used for receiving the second signal;

if the LPF in the AFE is closed and the LPF in the LD module is opened, the AFE is used for acquiring a first signal and sending the first signal to the LD module; the LD module is used for receiving the first signal and filtering the first signal through an LPF in the LD to obtain a second signal.

2. The transmitter of claim 1, wherein the AFE comprises a first LPF, a regulated voltage source, a first operational amplifier, and a second operational amplifier;

3. The transmission apparatus according to claim 1, wherein the AFE includes a second LPF, a first operational amplifier, and a second operational amplifier;

4. The transmission apparatus according to claim 2, wherein the AFE further comprises a third LPF;

5. The transmission apparatus according to claim 3, wherein the AFE further comprises a third LPF;

6. The transmission apparatus according to any one of claims 1 to 5, wherein the LD module includes a third operational amplifier, a fourth operational amplifier, a third resistor, a fourth LPF, and a fifth LPF;

7. The transmitting device of claim 6, wherein the LD module further comprises a sixth LPF and a seventh LPF;

8. A signal transmission method is characterized in that the method is applied to a sending device, the sending device comprises an analog front end AFE and a line driver LD module, the output end of the AFE is connected with the input end of the LD module, the AFE comprises at least one LPF, the LD module comprises at least one LPF, and each LPF is provided with a filtering frequency point; the LPF in the AFE comprises at least one switch for controlling the LPF in the AFE to be switched on or off; the LPF in the LD module comprises at least one switch for controlling the on or off of the LPF in the LD module; the method comprises the following steps:

acquiring a first signal;

determining a filtering frequency point according to the transmission frequency band of the first signal, wherein the filtering frequency point is greater than or equal to the highest frequency point of the transmission frequency band;

starting the LPF corresponding to the filtering frequency point, and filtering the first signal to obtain a second signal;

outputting the second signal.